Quarterly Financial Information (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest Income
Interest income	$ 17,464	$ 16,957	$ 16,741	$ 16,928	$ 17,064	$ 16,895	$ 16,541	$ 13,588	$ 68,090	$ 64,088	$ 45,393
Net interest income	16,123	15,396	15,242	15,498	15,726	15,571	15,197	12,437	62,259	58,931	41,526
Non-Interest Income
Non-interest income	2,061	2,806	2,271	3,001	2,354	2,982	2,476	1,763	10,139	9,575	12,875
Non-Interest Expense
Non-interest expense	12,774	12,151	11,429	11,813	11,385	13,382	12,986	17,039	48,167	54,792	36,563
Income before provision (benefit) for income taxes	5,410	6,051	6,084	6,686	6,695	5,171	4,687	(2,839)	24,231	13,714	17,838
Net income	3,478	4,002	3,800	4,069	4,352	3,429	2,949	(1,765)	15,349	8,965	10,841
Dividends and accretion on preferred stock			70		168				70	168	898
Net income available to common shareholders	$ 3,478	$ 4,002	$ 3,730	$ 4,069	$ 4,184	$ 3,429	$ 2,949	$ (1,765)	$ 15,279	$ 8,797	$ 9,943
Earnings Per Common Share
Basic (in dollars per share)	$ 0.10	$ 0.12	$ 0.11	$ 0.12	$ 0.13	$ 0.10	$ 0.09	$ (0.06)	$ 0.45	$ 0.27	$ 0.38
Diluted (in dollars per share)	0.10	0.12	0.11	0.12	0.13	0.10	$ 0.09	$ (0.06)	$ 0.45	$ 0.27	$ 0.37
Business Combination, Integration Related Costs									$ (77)	$ 9,190	$ 1,051
Dividends Declared Per Common Share (in dollars per share)	$ 0.06	$ 0.06	$ 0.06	$ 0.05	$ 0.05	$ 0.03			$ 0.23	$ 0.08
Heritage Oaks Bancorp
Interest Income
Interest income									$ 17	$ 16	19
Non-Interest Expense
Income before provision (benefit) for income taxes									9,060	8,569	23,859
Net income									15,349	8,965	10,841
Dividends and accretion on preferred stock									70	168	898
Net income available to common shareholders									$ 15,279	$ 8,797	$ 9,943